Machine for grinding formed cutters



W. 0. BARNES.

MACHINE FOR GRINDING FORMED CUTTERS.

A P P L l C A T I O N F I L E D 0 C T 2 5 1 9 I 9.

1,373,586. Patented Apr. 5, 1921.

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INVENTOR ATTORNEY W. 0. BARNES. MACHINE FOR GRINDING FORMED CUTTERS.

APPLICATION FILED OCT. 25, 1919.

1 ,373, v I Patented Apr. 5, 1921 4 SHEETS-SHEET 2.

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iii 26 3/ 3'2.

a i II I III-I INVENTOR ATTORNEY W. 0. BARNES.

MACHINE FOR GRINDING FORMED CUTTERS- APPLICATION FILED OCT. 25.19I9.

1,373,586. Patented Apr. 5, 1921.

/ 4 SHEETSfSHEET 3- INVENTOR ATTORNEY w. 0. BARNES. H MACHINE FOR GRINDING FORMED CUTTERS.

APPLICATION FILED OCT. 25, I919- '1,3'73,586 Patented Apr. 5,1921.

4 SHEETS-SHEET 4.

I \III IIIII I IIIIIII' llIlI I III YINV'ENTOR AI'TORNEY' UNITED STATES PATENT OFFICE.

WILLIAM 0. BARNES, OF LEOMINSTER,MASSACHUSETTS.

MACHINE FOR GRINDING FORMED CUTTERS.

Specification of Letters Patent.

Patented Apr. 5, 1921.

Application filed October 25, 1919. Serial No. 333,161. i

To all whom it may concern:

Be it known that 1, WILLIAM O. BARNES,

a" citizen of the United States, residing at claimed broadly in Letters Patent Nos.

1,196,420 and 1,236,898, issued to me August 29, 1916 and August14, 1917, respectively.

The present invention has for its objects to provide an improved machine for figrinda ing the profile faces of the teeth of irregularly formed cutters or similar irregular profiles, particularly those having curves of very small radius or sharp internal angles, to provide means for grinding, off the back portion of theprofile face of a tooth for reducing the width of said face when desired, and also to provide an improved wheel dressing and truing de vice for shaping the grinding wheel to the necessary contour.

With the foregoing and other objects in view, as will become apparent as the description proceeds, my invention consists in the elements, combinations and details of construction hereinafter described and claimed and illustrated in the accompanying drawings, wherein Figure l is a plan view of a grinding machine embodying the invention, the work- 4 holding being omitted.

Fig. '2 is a side elevation of the parts shown in Fig. 1.

Fig. 3 is a vertical sectional view taken just to the left of the grinding wheel, the

machine being shown in the act of grinding the profile face of a cutter.

Fig. 4 is a sectional view on the line 4-4 of Fig. 3, looking in the direction of the.

Fig. 6 1s a section on the line 6- -6 of raw. 3.

Fig. 7 is a view similar tp Fig. 5, the

grinding wheel being shown in a somewhat dliferent relation to the cutter tooth. Fig. 8 is a view similar to Fig. 6, showing the parts in the position corresponding to Fig. 7

Fig. 9 is a plan view of the work-holding jig, showing a cutter in position to be ground.

Fig. 10 is a front shown in Fig. 9.

Fig. 11 is a section on the line 11.11 of elevation of the parts ig. 12 is a section on the line 1212 of Fig. 9. i

Fig. plet used for grinding a cutter of the shape shown in Figs. 9 and 10.

Fig. 14 is a perspective view of the wheel truing" device in position for truing the grinding wheel.

Fig. 15 is anenlarged vertical sectional view of the truing device.

Fig. 16 is a perspective view of the rest support. 1

Fig. 17 is a perspective view of the guide sleeve.

constituting the present invention is similar: in many respects to that of the machines shown and described in the prior patents referred to above. The machine comprlses generally a grinding wheel of any suitable abrasive material mounted on a fiat table which'is provided with a guide having a contour, in horizontal section, identical'with the contour of a horizontal section of the grinding wheel taken at the grinding point. The cutter, or other article to be ground, is rigidly held in a suitable jigfreely slidable over the work table and provided with a suitable templet which may cooperate with the. guide for bringing'the cutter into the. .proper relation with the rotating grinding Wheel for accurately reproducing the templat form as the contour of the profile face of'the cutter teeth.-

13 is a perspectiveview of the tern tioned bydowel pins 24 and fastened in place by a suitable screw 25. The wheel slide 26 is carried in an aperture in said head and is slidable therein at a small angle to the horizontal (see Fig. 3). Said slide is provided with a pair of forwardly projecting and relatively closely adjacent yoke arms 27 which support the wheel shaft28 carrying a suitable grinding wheel 29 provided with a hub 30 rotatably mounted on said shaft as byball or other antifriction' bearings. Suitable means may be provided for rotating said wheel, as, for example, a belt (not shown) cooperating with a pulley portion 30 formed on said hub. The wheel slide may be adjusted by means of a feed screw 31 actuated by a suitable graduated feed knob 32, and is held in adjusted position by a binder screw 33 which may for convenient operation be provided with a handle 34. A suitable guard 35 is prefer ably provided for covering the grinding wheel, and, as in the'prior patents above referred to, a rest 36 is provided for supporting the cutter; tooth or other article to be ground.- This rest, as shown, is supported by a post 37 whose lower 'end is seated in an aperture 38 in the table.

As will be seen, the means above described for supporting the grinding wheel are such as to leave the sides of the wheel relatively unobstructed, so as to permit an increased freedom of movement of the work on both sides of the wheel, thereby facilitating the grinding of profiles having sharp curves and reentrant angles.

The numeral 39 (see Figs. 3 and 17) represents guiding .means, preferably in the form of a sleeve having a cross section corresponding to the horizontal section of the Wheel at the grinding point. This sleeve may be attached to the table in any desired manner, but ithas been found convenient and satisfactoryto form it with a tapered bore for receiving the preferably tapered stud portion 40 of the rest supporting post 37. The guide sleeve 39 may be further located and held against rotation by a pin 41 having a recess for receiving a corner of said sleeve (see Figs. 3, 6, and 14). This construction has the advantage of permitting the ready removal of a guide sleeve and the substitution therefor of another sleeve having a different cross section. These parts are preferably so positioned that the guide sleeve is in exact vertical alinement with the grinding wheel at the grinding point.

Means are provided for supporting the" i5 cutter or other artlcle to be ground; and

for bringing it into proper relation to the holding jig which, as shown in Figs. 9' to 12, consists of a pair of standards 51- and 52 connected by a base 53 carried by a plurality of supporting feet preferably in the .form of adjustable supporting screws 53. Carried by the standards 51 and 52 is a-work-holding arbor 54 adapted to receive thereon the cutter or other work 56, which arbor mayhave a flange 55, against which one end of said cutter 56 bears, and a collar 57 adjustable thereon for holding the cutter against said flange. The ends of the arbor are provided with journals 58 and 59 which, as shown in Figs. 9 and 11, are provided with transverse alined slots 60 and 61. These journals fit snugly in slots 62 and 63 in the upper ends of the standards 51 and 52 respectively. The slots 60 and 61 receive cylindrical studs 64 and 65 rigidly carried, eccentric to the arbor, by

blocks 66 and 67 firmly attached to the adjusted position by means of adjusting screws 70 and 71 bearing on opposite ends of said arbor at the inner ends of the slots 62 and 63, said screws passing axially through, and having threaded engagement with the studs 64 and 65, respectively. The arbor is adjusted vertically and maintained in its position of adjustment by means of an adjusting screw 73suitably guided for nonrotative vertical movement in an .opening in the standard 52 and engaging at its upper end the journal 59, said screw having a threaded portion to receive an adjusting nut 74 located in an aperture in said standard. It is necessary to provide but one such adjusting and supporting screw, since, when said screw is operated to raise or lower the journal 59, engagement of the eccentric stud 65 with the slot 61 will cause simultaneous rotation of said journal in its bearing slot 63, and the consequent rotation of the journal 58 in its bearing slot 62 will cause said journal 58, by reason of engagement of the stud 64 with the slot 60, to be raised and lowered in unison with the journal 59, andto the same extent, thereby maintaining the parallelism of the arbor with the work table. As in the construction shown in the prior patents above referred to, the arbor is so account of the inclination of the back of the tooth. If this widening of the profile face is carried beyond a certain limit, the

cutter becomes unserviceable because the back edges of the profile faces of the teeth will project more than the front or cutting *edges. It will become necessary, therefore, to narrow the face of each tooth by grinding away the back portion thereof. The jig described above is especially adapted for this purpose since, as above explained, by turning the nut 74 the arbor 54 maybe raised thereby bringing the back edge of the profile face of each tooth into a position where it may be reached and suitably ground down by the grinding wheel.

Means are provided for bringing the workinto the proper relation to the grind ing wheel, said -means, as herein shown, comprising a suitably formed templet 75 heldv parallel to the arbor and work table in opposed grooves 66 and 77 formed in the lower ends of the standards. For the purpose of suitably and adjustably supporting \the back face of the templet there is provided a pivoted adjusting bar 78, preferably mounted on pivot pins 7 9 in the standards. I This bar may be adjusted transversely by. means of a suitable adjusting screw 80.

The templet is held against the bearing face of said bar by a clamp bolt 81, having a nut 82 and an'inclined lug 83 receivable in ,a

corresponding slot 84 in the templet. This provides a convenient construction for ads I justably securingthe templet in'the proper relation to the cutter,

The peripheral edge of the grinding wheel is so shaped and positioned that a horizontal section thereof taken through the wheel at the top of the rest, 6. e., the grinding point, corresponds exactly in contour with the plan or horizontal section of the guide sleeve 39, and lies inexact vertical' alinement therewith.

Means are provided for forming the wheel withthis section, such means being preferably as follows. -The numeral 90 (see Figs. 14 and15) refers generally to sucha wheeltruing device which may consist of a bottom plate 91 supported by adjustable feet 92 and carrying a vertical threaded standard 93 located in a recess in the truing block 94 and supporting the latter at various points of vertical adjustment by means of the adjusting nut 95. The truing block is held against rotation by a guide pin 96 secured in the screw 97 which passes through'the plate91 from the underside and engages a threaded opening in the block 94, For cutting the grinding wheel to the desired form, there is provided a dressing tool or member98, prefplate 91 and .is positioned further by a guide be held in adjusted position by a pair of alined clamping pins 102 the inner of which engages said carrier, and the outer of which as shown, which allows the lower pin to bear evenly on the carrier. At its lower front portion, the block 94 is provided with guide Jugs 104 which cooperate with the cylindrical sides of'an oblong truing guide sleeve 106, which has an aperture 107 for receiving an eccentric portion 37 of the rest support 37, as shown in Fig. 14. The underside of the truing guide sleeve is formed with a central recess terminating, at opposite sides of the aperture 107, in shoulders 108 and 109, which are so formed and located as to snugly seat on the guide sleeve 39. In order to insure this snug seating without lostmotion, the shoulders 109 are v preferably slightly inclined. The cylindrical sides of the sleeve 106 are formed of the same curvature as the sleeve 106is seated on the sleeve 39, as above explained, one of said sides occupies a position approximately parallel to the adjacent face of said sleeve 39, thereby providing an extended bearing surface which may be followed by the lugs 104 to cause the diamond or other dressing member 98 to move in a path parallel to said face and consequently true the edge of the wheel by bringing the same into conformity with the configuration of thesleeve 39. The relative positions of the guide sleeve 39 and truing sleeve 106 will be clear from Figs 20 and 21, which illustrate diagrammatically the positions of the truing sleeve for dressing the opposite sides respectively, of the wheel.

In grinding cutters it is necessary, in order to obtain the necessary clearance angle on the teeth,'that theagrinding take place at a point below the horizontal diameter of the I grinding wheel, and the top of the rest 36 is correspondingly located, as will be clear from Fig. 3. As the truing of the wheel is effected on its horizontal diameter, the surface of the truing guide sleeve is not exactly in alinement with that of the guide sleeve 39, but is slightly displaced in the direction away from the wheel axis This displacement is secured by'forming the portion 37 eccentric to the taper portion 7 40. The amount of this eccentricity is exactly equal to the difi'erenc'e between the radius of the grinding wheel and half of its horizontal chord at thegrinding point. p

In order to accurately position the diamond 98 there may be employed a setting rod 105 normally kept in a recess in the grinding While the form of mechanism herein shownand described is admirably adapted to fulfil the objects of the invention, it is to carried by said arms, and a grinding wheel rotatably mounted on said shaft between saidarms. v

2. A machine for grinding irregular profiles comprising a table, a support fixedly mounted thereon, a pair ofarms adjustably carried by said support, a grinding wheel between said arms and carried thereby, a guide member in fixed relation to said table, and a templet movable over. said table in engagement with said guide member.

3. A machine for grinding irregular profiles comprising a table, a support fixedly mounted thereon, a pair of arms adjustably carried by said support, a grinding wheel between said: arms and carried thereby, a guide memberin fixed relation to said table, a'jig provided with means for holding the article to be ground,,andfia'templet carried by said jig and positioned to be engageable with said guide member.

4. A machine for grinding profile faces of formedcutter teeth comprising a table, a grinder supported'above said table, a rest for cutter teeth, and a guide sleeve carried by said rest. a i

' 5; In a machine for grinding the profile I faces of formed cutter teeth, the combination with a grinding wheel, of a work support, a bodily movable arbor, and means for maintaining the parallelism of the arbor with the work support when the arbor is moved. r

6. In a machine for grinding the profile faces of formed cutter teeth, the combination with a grinding wheel, of a work sup-1 port having an arbor disposedwith its axis transverse to the periphery of said wheel,

grinding means forsaid work support including a templet parallel to the axis of said arbor, said arbor being bodilymovable with respect to'said templet, and means for preservi'ngthe parallelism bf said arbor and templet. i

' 7. A work-holding jig for grinding machines comprising'a pair of standards-,an

arbor vertically movable in said standards,

/ and means for maintaining the parallelism of the arbor with the jig when the arbor is vertically moved.

8. In a machine faces of formed cutter teeth, the combination with a vertically disposed grinding wheel, of a horizontally and vertically movfor grinding the profile able arbor disposed transversely to said grinding wheel for presenting work thereto, and means for maintaining'the parallelism of said arbor when the same is vertically moved.

99A work-holding jig for grinding machines comprising an arbor having ends provided with transverse slots, supporting standards formed with slots for receiving the ends of the arbor, and eccentric studs carried by the standards and received in the slots in the arbor.

10. 'A work-holding jig for grinding machines comprising an arbor having ends I provided with transverse slots, supporting standards formed with slots for receiving the ends of the arbor, eccentric studs car ried by the standards and received in the slots in the arbor, and means for raising and lowering said arbor.

11. A work-holding-jig for grinding machines comprising an arbor having ends provided with transverse slots, supporting standards formed with slots for receiving the ends of the arbor, eccentric studs car'- ried by the standards and received in the slots in the arbor, and blocks rigidly secured to said standards and by which said studs are, carried.

12. A work-holding jig for 'grinding machines comprising an arbor having ends provided with transverse slots, supporting standards formed with slots for receiving theends of the arbor, eccentric studs carried by thestanda'rds and received in the slots in the arbor, and anadjusting screw carried by one of said standards and engaging one end of said arbor for raising and lowering the same.

13. A work-holding jig for grinding machines comprising an arbor" having endsprovided with transverse slots, supporting standards formed with slots for receiving .the ends of the arbor, eccentric stu'ds carried by the standards and received in the.

slots in the arbor, and adjusting screws carried by said standards and engaging theinner ends of saidlast named slots for longitudinally adjusting said arbor.-

chines comprising an arbor, supporting standards therefor having opposed grooves,

a templet slidable in said grooves, an ad-' justable bar against which said templet bears, and means for holding said templet against said bar.

14. A work-holding jig for grinding ma- 15. A work-holding jig for grinding machines comprising an arbor, supporting standards therefor, opposed grooves in said 16. A machine for grinding irregular prostandards, a templet slidable in said grooves ,files comprising a table, a grinding Wheel and provided With a recess, an adjustable supported above said table, a. supporting 10 bar against Which said templet bears, and a post fixed to said table, and a guide sleeve bolt formed with an inclined lu received carried by said post.

in said recess for holding said temp et against In testimony whereof-I aflix rny signature. said bar. WILLIAM O. BARNES. 

